Rapidly dissolvable polymer films and articles made therefrom

ABSTRACT

A film-forming composition for use in preparing water-soluble films that are rapidly dissolving under cold water conditions, the composition comprising a water soluble polymer material such as polyvinyl alcohol and a principal solvent, typically diol(s) or derivative of a diol. Films made from the film-forming compositions may be used to encapsulate a variety of compositions for subsequent release into an aqueous medium. Encapsulated compositions can include various laundry detergents and additives, fabric care compositions such as fabric softening compositions and dishwashing detergents among others. When used to encapsulate compositions, the solvent system used in the film-forming composition will have at least one common solvent material as the solvent system used in the encapsulated composition to improve film dissolution and to prevent problems associated with solvent migration.

FIELD OF THE INVENTION

[0001] The present invention relates to the development and use ofwater-soluble polymer materials and films and articles made therefromthat are readily dissolvable in cold water. The present invention iseven more particularly related to the use of such polymer materials informing water-soluble articles that contain a variety of consumerproduct compositions including but not limited to laundry and fabriccare compositions, and other compositions that are commonly used and/ordiluted in cold water.

BACKGROUND OF THE INVENTION

[0002] Water-soluble films and their use in forming water-solublearticles are well known in the art.

[0003] U.S. Pat. No. 3,186,869, issued Jan. 29, 1962, COATED FILM FORLAUNDRY PACKAGE, and U.S. Pat. No. 3,322,674, issued Jun. 26, 1964,LAUNDRY PACKAGE, disclose water-soluble films and laundry articles madetherefrom which contain a detergent and chorine based bleaching agent.The water-soluble films in these references are internally coated with awax or other material to prevent the contents of the package frominteracting with the film material and degrading its solubilitycharacteristics.

[0004] U.S. Pat. No. 3,413,229, issued Nov. 26, 1968, POLYVINYL ALCOHOLCOMPOSITIONS, teaches the use of a plasticizer in PVA compositions thatare used to form laundry packets for detergents and/or bleaches in orderto maintain the solubility characteristics of the film after storage.

[0005] U.S. Pat. No. 3,892,905, issued Jul. 1, 1975, COLD WATER SOLUBLEPLASTIC FILM, discloses a cold water soluble film that comprises acombination of polymers having different molecular weights. The lowestmolecular weight polymer suggested is about 21,000.

[0006] U.S. Pat. No. 4,119,604, issued Oct. 10, 1978, POLYVINYL ALCOHOLCOMPOSITIONS FOR USE IN THE PREPARATION OF WATER-SOLUBLE FILMS,discloses a cold water soluble film that comprises a low molecularweight PVA and a medium molecular weight PVA. The “low” and “medium”molecular weights are not identified but are merely described in termsof the viscosity of a solution containing the polymer.

[0007] U.S. Pat. No. 4,481,326, issued Nov. 6, 1984, WATER-SOLUBLE FILMSOF POLYVINYL ALCOHOL AND POLYVINYL PYRROLIDONE, discloses a cold watersoluble film for packaging various products. The film compriseshydrolyzed polyvinylacetate alcohol and polyvinyl pyrrolidone. Specificdata concerning the dissolution rate of the film in cold water is notdisclosed.

[0008] U.S. Pat. No. 4,544,693, issued Oct. 1, 1985, WATER-SOLUBLE FILM,discloses a water-soluble film that reportedly dissolves in water ascold as 5° C. The film is composed of polyvinyl alcohol, polyvinylpyrrolidone, ethoxylated alkyphenol, and polyhydric alcohol. Nodissolution data concerning the claimed film is provided.

[0009] U.S. Pat. No. 4,692,494, issued Sep. 8, 1987, WATER-SOLUBLE FILMSOF POLYVINYL ALCOHOL AND POLYACRYLIC ACID AND PACKAGES COMPRISING SAME,discloses a cold water soluble film made of a blend of PVA andpolyacrylic acid.

[0010] U.S. Pat. No. 4,765,916, issued Aug. 23, 1988, POLYMER FILMCOMPOSITION FOR RINSE RELEASE OF WASH ADDITIVES, discloses water-solublelaminate film that comprises at least one methylcellulose layer ofhydroxybutyl methylcellulose (HBMC) blended with hydroxypropylmethylcellulose (HPMC) and at least one layer of polyvinyl alcoholincorporating a cross-linking agent. The solubility of the laminate isintended to be pH rather than temperature dependent.

[0011] U.S. Pat. No. 4,801,636, issued Jan. 31, 1989, RINSE SOLUBLEPOLYMER FILM COMPOSITION FOR WASH ADDITIVES discloses a water-solublefilm that is made from a blend of polyvinyl alcohol and alkyl celluloseand has a metalloid oxide component to inhibit the dissolution of thefilm in an alkaline wash but allow dissolution in the less alkalinerinse. U.S. Pat. No. 4,972,017, issued Nov. 20, 1990, is a divisional ofU.S. Pat. No. 4,801,636 that is directed to an article made from thefilm claimed in the '636 patent.

[0012] U.S. Pat. No. 5,272,191, issued Dec. 21, 1993, COLD WATER SOLUBLEFILMS AND FILM-FORMING COMPOSITIONS discloses water-soluble film madefrom known water-soluble film-forming polymers, and a second componentthat is a water insoluble cellulose material. The cellulose is renderedinsoluble preferably through internal or external cross linkingreactions.

SUMMARY OF THE INVENTION

[0013] The present invention provides a film-forming composition forforming a cold water soluble film, the composition comprising:

[0014] from about 50% to about 99.9% of a water-soluble polymer materialand

[0015] from about 0.1% to about 50% of a principal solvent, wherein afilm formed from the film-forming composition will dissolve in a beakerof water at a temperature below about 68° F. with agitation, in lessthan about 5, preferably less than about 4, still more preferably lessthan about 3 and even more preferably less than about 2 minutes.

[0016] The present invention further provides for a water-soluble filmformed from the film-forming composition as well as an article wherein acomposition to be dispensed into an aqueous medium is enclosed orencapsulated in the cold water soluble film.

DETAILED DESCRIPTION OF THE INVENTION

[0017] All percentages, ratios and proportions herein are by weight,unless otherwise specified. All temperatures are in degrees Celsius(°C.) unless otherwise specified. All documents cited are incorporatedherein by reference in their entireties. Citation of any reference isnot an admission regarding any determination as to its availability asprior art to the claimed invention.

[0018] As used herein, “comprising” means that other steps and otheringredients which do not affect the end of result can be added. Thisterm encompasses the terms “consisting of” and “consisting essentiallyof”.

[0019] As used herein, “cold water conditions” is intended to refer toan environment where there is sufficient water to dissolve the film,i.e. the concentration of film polymer does not exceed its solubilitylimit in cold water, and where the temperature of the water is less thanabout 68° F. and more preferably is less than about 50° F. It isanticipated that the improvements in dissolution achieved with the filmsand articles of the present invention will likely be seen under warm andhot water conditions as well.

[0020] As used herein, “rapidly dissolving” is intended to refer to thedisintegration and subsequent dissolution of the polymer film in lessthan about 5 minutes, preferably less than about 3 minutes and morepreferably less than about 2 minutes after the film or an article madetherefrom is placed in cold water conditions.

[0021] Film-Forming Compositions

[0022] The film-forming compositions of the present invention comprisewater-soluble film-forming polymer material and principal solvent.Optionally, the film-forming compositions may contain a variety ofadjunct ingredients that are well known to those in the film-formingart. Each of these components can be varied according to the levelsdesired in a given cold water soluble film.

[0023] A. Water-soluble Film-forming Polymers

[0024] Any water-soluble, film-forming polymer, or mixtures of polymers,may be used in the film-forming compositions of the present invention.The polymers usually are vinyl polymers, including homopolymers andcopolymers, having functionality rendering the polymers water-soluble,such as hydroxyl and carboxyl groups. Typical water-soluble polymersinclude at least one of polyvinyl alcohol, partially hydrolyzedpolyvinyl acetate, polyvinyl pyrrolidone, alkyl celluloses such asmethylcellulose, ethylcellulose, propylcellulose and derivativesthereof, such as the ethers and esters of alkyl celluloses, and acrylicpolymers such as water-soluble polyacrylates, polyacrylamides, andacrylic maleic anhydride copolymers. Suitable water-soluble polymersfurther include copolymers of hydrolyzed vinyl alcohol and anonhydrolyzable anionic comonomer, such as described in U.S. Pat. No.4,747,966 to Yang et al, cited above.

[0025] It will be evident that a wide variety of film-formingwater-soluble polymer materials, including synthetic and naturalpolymers, and mixtures thereof, as described in standard textbooks onthe subject and in the patent literature may be used to advantage. Forexample, in addition to the U.S. patents cited above, Japaneseunexamined patent applications JP 01317506A published Dec. 22, 1989, andJP 60061504A published Apr. 9, 1985, describe water-soluble films ofpolyvinyl alcohol, polyvinyl pyrrolidone, methylcellulose, celluloseacetate, polyethylene oxide, gelatin, partially saponified polyvinylalcohol, CMC, dextrin, starch, hydroxyethyl cellulose, agar, pectin, andothers for the packaging of process chemicals such as sodium sulfate andsolid agricultural chemicals. Similarly, British Patent 2,191,379granted Dec. 16, 1987, describes the packaging of animal feedsupplements in a plastic film of polyvinyl alcohol, polyvinyl acetate,ethylene/vinyl acetate copolymer or an alkylcellulose ester. Thedisclosures of all of the above cited patents and patent applicationsare incorporated herein by reference.

[0026] Particularly preferred film-forming polymers are polyvinylalcohol, vinyl alcohol/vinyl acetate copolymers, polyvinyl pyrrolidone,gelatin, and mixtures of any of the foregoing. Polymer films comprisingpolyvinyl alcohol can be prepared that are particularly rapidlydissolvable at colder temperatures i.e. less than about 50° F. or lessthan about 40° F. Further, polyvinyl alcohols having varying averagemolecular weights (i.e. mean weights of the molar masses) such as fromabout 6,000 to about 78,000 or higher may be used. Likewise, polyvinylalcohol having varying degrees of hydrolysis may also be used toadvantage. Preferably, such polymers are less than about 90%, morepreferably less than about 85%, and still more preferably less thanabout 80% hydrolyzed, but will be more than about 60% and morepreferably at least about 70% hydrolyzed. Blends of water-solublepolymers having different degrees of hydrolysis may also be used toadvantage. Other preferred film-forming polymers include polyethyleneoxide, polyvinyl pyrrolidone, hydroxypropyl methylcellulose andhydroxyethylcellulose.

[0027] Blends of water-soluble film-forming polymers may also be used toadvantage. Blends offer additional advantages in that rapidly dissolvingfilms can be produced with good mechanical properties for subsequenthandling and converting into manufactured articles. For instance, ablend containing at least two types of water-soluble polymers that havedisparate molecular weights, can be used to prepare film that is rapidlydissolving under cold water conditions. Preferably, such blends containat least one type of polymer that has a molecular weight greater thanabout 50,000, preferably greater than about 60,000 and even morepreferably greater than about 70,000, and a second polymer or mixture ofpolymers having an average molecular weight of less than about 30,000,more preferably less than about 15,000, and even more preferably lessthan about 10,000.

[0028] More specifically, a blend of at least one polyvinyl alcoholhaving a molecular weight of about 78,000 and higher and a secondpolyvinyl alcohol about 6,000 or lower has been found to produce arapidly dissolving film under cold water conditions. A low percentage ofthe higher molecular weight polyvinyl alcohol, namely, less than about50% preferably less than about 40%, and more preferably less than about30%, will produces a film with adequate strength for converting intosachets or coatings. A higher percentage of higher molecular weightpolyvinyl alcohol, namely, greater than about 50%, preferably greaterthan about 60% and more preferably greater than about 70%, will providethe improved strength and elasticity that is desired for vacuum formingoperations, but it should be noted that such higher percentages of highMW polymers are typically accompanied by increasingly higher dissolutiontimes. Blends of high and low molecular weight polymers at ratios of80/20, 60/40, and 50/50 mixtures of low to high molecular weightpolyvinyl alcohol can be evaluated for specific applications.

[0029] By way of example, a rapidly dissolving film can be prepared froma blend of polyvinyl alcohol that comprises from about 60% to about 95%of polyvinyl alcohol of an average molecular weight from about 3,000 toabout 30,000 and from about 5% to about 40% of polyvinyl alcohol of anaverage molecular weight from about 30,000 to about 200,000. The degreeof hydrolysis in the polyvinyl alcohol blend is preferably less thanabout 90 mol %, more preferably less than about 85% mol %, and stillmore preferably less than about 80 mol %. The film formed from thiscomposition can dissolve in a beaker of water at a temperature belowabout 68° F. in less than about 5 minutes with agitation.

[0030] In addition, blends of different types of polymer materials canalso be formulated and prepared to produce the films of the presentinvention. For instance, ratios of 80/20, 60/40 and 50/50 with mixes ofpolyvinyl alcohol and polyvinyl pyrrolidone, polyvinyl alcohol andpolyethylene oxide, polyvinyl alcohol and hydroxyethyl cellulose,polyvinyl pyrrolidone and hydroxyethyl cellulose, polyvinyl pyrrolidoneand polyethylene oxide, and polyethylene oxide and hydroxyethylcellulose, hydroxypropyl methylcellulose and polyvinyl alcohol, can beused to advantage.

[0031] B. Principal Solvent

[0032] The film-forming compositions of the present invention compriseless than about 50%, preferably from about 5% to about 35%, morepreferably from about 8% to about 25%, and even more preferably fromabout 10% to about 20%, of the principal solvent, by weight of thecomposition. Said principal solvent is selected to minimize the timerequired for the water-soluble film to disintegrate and dissolve undercold water conditions. Dissolution data on films with and without aprincipal solvent is presented below following the section entitled“Solubility Test Method.”

[0033] The suitability of any principal solvent for the formulation ofthe film-forming composition herein is surprisingly selectiveconsidering solubility, film mechanical properties, and compatibilitywith the composition to be encapsulated by the film. Suitable solventscan be selected based upon the octanol/water partition coefficient (P)of the solvent itself, and other solvent-polymer interactions. Theprincipal solvent may also consist of a mixture of these materials,which may result in an improvement in both film solubility andmechanical properties.

[0034] The octanol/water partition coefficient of a principal solvent isthe ratio between its equilibrium concentration in octanol and in water.The partition coefficients of the principal solvent ingredients of thisinvention are conveniently given in the form of their logarithm to thebase 10, ClogP.

[0035] The logp of many ingredients has been reported; for example, thePomona92 database, available from Daylight Chemical Information Systems,Inc. (Daylight CIS), Irvine, Calif., contains many, along with citationsto the original literature. However, the logP values are mostconveniently calculated by the “CLOGP” program, also available fromDaylight CIS. This program also lists experimental logP values when theyare available in the Pomona92 database. The “calculated logP” (ClogP) isdetermined by the fragment approach of Hansch and Leo (cf., A. Leo, inComprehensive Medicinal Chemistry, Vol. 4, C. Hansch, P. G. Sammens, J.B. Taylor and C. A. Ramsden, Eds., p. 295, Pergamon Press, 1990,incorporated herein by reference). The fragment approach is based on thechemical structure of each ingredient, and takes into account thenumbers and types of atoms, the atom connectivity, and chemical bonding.The ClogP values, which are the most reliable and widely used estimatesfor this physicochemical property, are preferably used instead of theexperimental logP values in the selection of the principal solventingredients which are useful in the present invention. Other methodsthat can be used to compute ClogP include, e.g., Crippen's fragmentationmethod as disclosed in J. Chem. Inf. Comput. Sci., 27, 21 (1987);Viswanadhan's fragmentation method as disclose in J. Chem. Inf. Comput.Sci., 29, 163 (1989); and Broto's method as disclosed in Eur. J. Med.Chem.—Chim. Theor., 19, 71 (1984).

[0036] The principal solvents herein are selected from those having aClogP of from about −2 to about 2.6, preferably from about −1 to about1, more preferably from about 0.15 to about 0.64, and even morepreferably from about 0.40 to about 0.60, and said principal solventpreferably being asymmetric. Solvents that have a low molecular weightand are biodegradable are also desirable for some purposes. The moreasymmetric solvents appear to be very desirable, although highlysymmetrical solvents, having a center of symmetry such as1,4-cyclohexanedimethanol, are also preferred.

[0037] Examples of preferred principal solvents include alcohols, and inparticular polyols such as diols. Specific non-limiting examples ofpreferred principal solvents include 1,4-butanediol, 1,3 butanediol and1,2-hexanediol, 2,2,4-trimethylpentanediol, ethoxylates of2,2,4-trimethylpentanediol, 2-ethyl 1,3 hexanediol, and 1,4cyclohexanedimethanol, and 1,2 cyclohexanedimethanol. For moleculesexhibiting isomerism, both the trans and cis forms can function asprincipal solvents. An extensive description of materials suitable foruse as principal solvents and as “simple” solvents are disclosed in U.S.Pat. No. 6,323,172, issued Nov. 27, 2001 to Trinh, et al., which isincorporated herein by reference.

[0038] In selecting the principal solvent for incorporation into awater-soluble film, for example a polyvinyl alcohol film, it isimportant to consider the composition of the material to be encapsulatedby the film. In particular, it is known that solvents in the compositionmay migrate into the film over time. This can cause a loss of integrityto the film by affecting its physical and mechanical properties. Forexample, the film and articles made therefrom, e.g., a pouch, sachet orbead, can become soft losing the ability to maintain their shape and/oreven their structural integrity. This migration of materials from thecomposition into the film may also cause the composition inside thearticle to become cloudy, viscous and/or exhibit poor dispersionproperties due to the loss of solvent. Likewise, solvents and/orplasticizers in the film can migrate into the composition encapsulatedby the film. This migration can also alter the encapsulated materialcausing it to become less desirable or effective in performing itsintended function.

[0039] To avoid issues relating to solvent migration, it is preferredthat the principal solvent (or mixture of solvents) in the filmcomposition comprise at least one common solvent that is present in theencapsulated composition. For example, if the composition to beencapsulated is a fabric enhancer product such as is described in WO01/85892 Al, which preferably comprises 1,4-cyclohexanedimethanol, thenpreferably the film composition should also comprise1,4-cyclohexanedimethanol to mitigate against solvent migration and thedeleterious effects that can result therefrom.

[0040] As noted above, the incorporation of a principal solvent in thefilm forming composition can also improve the dissolution properties ofa film. It is well known that specific materials can render a filminsoluble delaying or preventing the disintegration and opening ofwater-soluble articles made from the film, and/or inhibiting thecomplete dissolution of the film material after the article has opened.There is particular concern that when the contents encapsulated in awater-soluble are released to the aqueous medium, those materials mayinhibit the complete dissolution of the remaining film material.However, it has been found that the use of at least one principalsolvent in the film material that is the same as one of the solventsused in the encapsulated composition will promote faster dissolution ofthe remaining film material. Compatibility between the film comprising aprincipal solvent and the encapsulated composition may be determined byusing the beaker test method that is described below.

[0041] Suitable solvents can also include low molecular weight alcohols,polyols, alcohol ethoxylates and the like. In addition, hydrotropes suchas sodium toluene sulfonate, sodium butyrate, sodium cumene sulfonate,sodium xylene sulfonate, and other hydrotropic materials can also beused to improve the cold water solubility of the film composition.

[0042] C. Adjunct Ingredients

[0043] The film-forming polymer may be further modified with variousreagents commonly employed in the film preparation art such asplasticizers, surfactants, anti-block agents, antifoamers, defoamers,biocides, perfumes, colorants, opacifiers, pearlescing agents, and thelike.

[0044] To help provide flexibility to the film a plasticizer may beincluded in the film-forming composition. The amount of plasticizer canrange from 0% to about 40%, by weight of the film-forming polymer. Asshown in the examples below, it is preferred that the film compositionhave between about 2% to about 5% of a plasticizer. Suitableplasticizers include glycerine, urea, poly(alkylene glycols) such asethylene glycol, trimethylene glycol, tetramethylene glycol,pentamethylene glycol, hexamethylene glycol, propylene glycol,diethylene glycol, and triethylene glycol, alkane diols such as 1,2propanediol, 1,3 propanediol, 2,3-butanediol, 1,4-butanediol,1,3-butanediol, 1,5-pentanediol, and 1,6 hexanediol; alkanolamines suchas triethanolamine; alkanolamine acetates such as triethanolamineacetate; and alkanolacetamides such as ethanol acetamide. Whileglycerine is preferred for most purposes, selection of an appropriateplasticizer is made according to the ultimate required properties of thefilm. It is important to note that some materials have dual functionserving both as a principal solvent and as plasticizer. Thus, severalmaterials that are identified above as principal solvents are alsodescribed herein as suitable plasticizers.

[0045] Representative of surfactants conventionally employed in theproduction of water-soluble films include water-soluble anionicsurfactants such as carboxylate soaps, alkylarylsulfonates,alkanesulfonates, alpha-olefinsulfonates, fatty alcohol sulfates, andoxo-alcohol ether sulfates described in the technical literatureincluding U.S. Pat. No. 3,634,260 cited above and others. A preferredanionic surfactant class comprises alkali metal salts of sulphated fattyalcohols containing about 10 to about 18 carbon atoms, such as sodiumlauryl sulfate and sodium stearyl sulfate. Suitable nonionic surfactantsinclude the alkylphenol ethoxylates, fatty or oxo-alcohol polyethyleneglycol ethers, ethylene oxide-propylene oxide block copolymers, fattyalcohol polygylcol ethers and ethoxylated fatty alcohols. To a lesserextent amphoteric or cationic surfactants may also be employed in thefilm-forming compositions of the invention, such as the alkyl betaines(sulfonated or nonsulfonated), quarternary ammonium salts and amineoxides. The surfactants may be used in amounts normally effective toassist in dispersion of water-soluble polymers, such as about 1% toabout 30% by weight of total film-forming composition.

[0046] Antifoam agents include the silicon polymers and defoamersinclude tallow compounds.

[0047] Useful biocides comprise any of the many known materials havingefficacy against bacteria and other degrading organisms but which arenon-toxic to handlers and to mammals or persons in the environment ofuse. Such agents and the principles of selection are well known to thoseskilled in the art. Suitable biocides include quarternary ammonium saltssuch as alkyl(C8-C18)di(lower alkyl)benzylammonium chloride anddialkyldimethylammonium bromide.

[0048] Procedure For Making Polymer Films

[0049] A 250 ml beaker, stir bar and stirring hot plate can be used tomake the polymer films in the laboratory hood. First, the desiredcomponents are weighed out on a balance to obtain the desired percentagelevels into the beaker. Distilled water and a stir bar are added to thebeaker. The beaker is placed on the hot plate to stir until all thecomponents are completely dissolved. Finally, the solution is pouredonto teflon plates to let the water evaporate off until the film isformed. This evaporation method usually takes about 1 to about 3 days.The dried film preferably has a thickness between about 20 microns andabout 80 microns. Film-forming Composition Examples PVA** PVA** (M.W.6,000, 80% (M.W. 78,000, 88% Sample Film hydrolysis) hydrolysis) % CHDM1 80% (˜2.0 g) 0 20% (˜0.5 g) 2 47% (˜1.3 g) 33% (˜0.9 g) 20% (˜0.5 g)

[0050] Film Examples PVA (M.W. 6,000, 1,6- Glycer- Film 80% hydrolysis)PVP POE CHDM hexanediol ine 1 50% 30% 0 18% 0 2% 2 40% 0 40% 0 18% 2%

[0051] The film-forming compositions of the invention can be made intofilms of varying thickness on a commercial scale using conventionalmethods and techniques such as solution casting and thermo-formingtechniques. Films prepared from the film-forming compositions of thepresent invention are preferably in the range of about 20 to about 100microns in thickness, and more preferably between about 20 microns andabout 80 microns.

[0052] In addition, the films of the present invention can be usedeffectively in the preparation of laminated or other multi-layeredfilms. For example, an encapsulate formed from a two layer film cancomprise of an inner layer made from a high molecular weight polyvinylalcohol and/or a low degree of hydrolysis resin to provide a barrierlayer in contact with a material or composition that is encapsulated inthe film. A second outer layer comprising a low molecular weight and/orhigh degree of hydrolysis polyvinyl alcohol resin and a principalsolvent may be desirably to provide fast dissolution at theencapsulate's surface. In addition to compositional differences, thethickness of various layers would likely differ; the inner layer havinga thickness in the range of about 10 to about 40 microns and the outerlayer having a thickness in the range of about 30 to about 60 microns.Further, it may be desirable to provide a layer of material intermediatebetween film layers to aid in the handling and processing of multi-layerfilms.

[0053] In solution casting, the compositions are cast on a plate or beltusing a film applicator where they are allowed to dry. The films canthen be vacuum-dried, followed by removal from the coating plate/belt.Casting techniques are described in greater detail in U.S. Pat. No.5,272,191 issued Dec. 21, 1993 to Ibrahim, et al. which is incorporatedherein by reference.

[0054] Films may also be prepared by a melt process, which typicallyinvolves mixing the components together with sufficient water to allowthe polymer and principal solvent to melt at a temperature below theirdecomposition temperatures. The blended material is fed to an extruder,extruded under tension through an appropriate die, cooled with air andtaken up by an appropriate collection device. For making films, atubular film can be made with cool air being blown through the center ofthe tube to both cool the film and to impart a biaxial stress to thefilm. Extrusion processes can also be used to make other shaped articlesby using appropriate dies and molds. Examples of such thermo-formingprocesses are described in greater detail in U.S. Pat. No. 5,646,206issued Jul. 8, 1997 to Coffin, et al., said patent being incorporatedherein by reference.

Solubility Test Method

[0055] To determine the solubility of polymer films in cold water (40°F.) a simplified beaker test method was employed. More specifically, thebeaker test method was used to determine the amount of time it takes forthe film to break up into pieces (disintegration) and to dissolvecompletely (dissolution) by placing the film sample in a beakercontaining water at 40° F. with constant agitation.

[0056] The methodology consisted of cutting a sample of each film about2 in. by 2 in. square and placing it in a 250 ml beaker containing about100 g of cold water. A stirring bar was added and the beaker placed on aCorning® magnetic stir/hot plate, model number PC-420. The film andwater were stirred at a constant low speed (setting =3) until the pieceof film appeared to be completely dissolved visually. In determiningfilm solubility in a medium that does not allow visual inspection of thefilm (i.e. a fabric softening composition), the contents of the beakerwere poured through a strainer having openings of about 1 mm in diameterto catch any portions of the film that were not completely dissolved.When remnants of the film were caught in the strainer, the remnants weretransferred back to the beaker and the stirring continued until the filmcompletely dissolved. When the beaker contents pass through the strainerwithout leaving residue in the strainer, dissolution was complete. Thedissolution time required for the film to be able to pass through thestrainer without leaving residue was then recorded.

[0057] The following table provides film dissolution data concerningdifferent films with and without a principal solvent as well as dataconcerning the interaction of the encapsulate composition with the filmmaterial and the inhibitory effect on the dissolution of the film. Forfilms dissolved in pure water and films dissolved in a fabric softeningcomposition, the dissolution times are dramatically shortened by theincorporation of a principal solvent into the film-forming composition.For films dissolved in pure water, the dissolution time of a film with aprincipal solvent were only about 25% to about 27% of the dissolutiontimes for films that did not comprise a principal solvent. Similarly,for films dissolved in a fabric softening composition, the dissolutiontime of a film with a principal solvent were about 40% of thedissolution time for films that did not comprise a principal solvent.Film Dissolution Film Dissolution Film Dissolution Time in 40° F. Timein Fabric Hydrolysis 1,4-CHDM Water Softener* Film (%) MW (%) (min:sec)(min:sec) PVA 80 6,000 20 0:45 0:56 PVA 80 6,000 0 2:44 2:20 PVA 50/50mix of 50/50 mix 20 1:15 4:00 80% & 88% of 6,000 & 78,000 PVA 50/50 mixof 50/50 mix 0 5:00 10:00  80% & 88% of 6,000 & 78,000

[0058] Articles

[0059] Films made of the film-forming compositions of the presentinvention have a variety of useful applications. They are useful ascoatings, adhesives, and in particular are useful in formingwater-soluble articles such as pouches for dispensing pre-measuredand/or hazardous substances. By way of example, pouches and theirmanufacture are described in additional detail in U.S. Pat. No.4,801,636, issued Jan. 31, 1989 to Smith, et al. and U.S. Pat. No.6,281,183, issued Aug. 28, 2001 to Harbour, both of which areincorporated herein by reference. Controlled release matrices, carriersor coatings that are water-soluble also have numerous applications suchas the application of pharmaceutical preparations to the skin fortransdermal delivery. Biodegradable materials that are carrier matricessuch as tablets or encapsulation materials are also contemplated.

[0060] The range of materials that can be encapsulated and sealed withinthe films of the present invention is very broad and includes virtuallyany composition which is functional in a cold water environment or whichmay be conveniently diluted in cold water before its intended use orapplication. The primary limitation is the water content of thecomposition. More specifically, it is difficult to encapsulatecompositions that have a high water content as such compositions tend tocause premature dissolution of the films.

[0061] Specific examples of compositions that are suitable forencapsulation water-soluble film for subsequent dispersing in filmsinclude detergents and other laundry compositions including fabricsoftening compositions. Non-limiting examples of fabric softeningcompositions that may be encapsulated are described in U.S. Pat. No.5,861,370, which issued Jan. 19, 1999 to Trinh, et al., U.S. Pat. No.6,323,172 B2, which issued Nov. 27, 2001 to Trinh, et al. and U.S. Pat.No. 6,335,315 B2 which issued Jan. 1, 2002 to Trinh, et al., all of saidpatents being incorporated herein by reference. All manner ofcompositions that require dilution in an aqueous medium prior to use maybe encapsulated in the films and articles of the present invention.

[0062] Encapsulating a composition in a water-soluble film can beaccomplished using conventional techniques and equipment. Encapsulationprocesses that utilize vacuum forming are known in the art as describedin U.S. Pat. No. 6,281,183 B2, issued Aug. 28, 2001 to Harbour, which isincorporated herein by reference. Equipment for performing suchencapsulation processes is commercially available for instance fromCloud Corporation, Des Plaines, Ill.

What is claimed is:
 1. A film-forming composition for forming a coldwater soluble film, the composition comprising: from about 50% to about99.9% of a water-soluble polymer; and from about 0.1% to about 50% of aprincipal solvent wherein a film formed from the film-formingcomposition will dissolve in a beaker of water at a temperature belowabout 68° F. in less than about 5 minutes with agitation.
 2. The polymerfilm composition of claim 1, wherein the water-soluble polymer comprisesa polyvinyl alcohol.
 3. The polymer film composition of claim 2, whereina film formed from the film-forming composition will dissolve in abeaker of water at a temperature below about 50° F. in less than about 2minutes with agitation.
 4. The polymer film composition of claim 1,wherein the water-soluble polymer comprises a mixture of twowater-soluble polymers having disparate molecular weights.
 5. Thepolymer film composition of claim 4, wherein the water-soluble polymercomprises a first polymer having a molecular weight greater than about50,000, preferably greater than about 60,000 and even more preferablygreater than about 70,000 and a second polymer having a molecular weightof less than about 30,000, more preferably less than about 15,000, andeven more preferably less than about 10,000.
 6. The polymer filmcomposition of claim 4, wherein the ratio of high to low molecularweight polymers is greater than about 50/50, more preferably greaterthan about 40/60, and even more preferably greater than about 30/70. 7.The polymer film composition of claim 2, wherein the polyvinyl alcoholis at least partially hydrolyzed.
 8. The polymer film composition ofclaim 7, wherein the polyvinyl alcohol is less than about 90%hydrolyzed.
 9. The polymer film composition of claim 7, wherein thepolyvinyl alcohol is a mixture of at least two polyvinyl alcoholmaterials, the two polyvinyl alcohol materials having different levelsof hydrolysis.
 10. The polymer film composition of claim 1, wherein theprincipal solvent is an alcohol.
 11. The polymer film composition ofclaim 1 additionally containing a surfactant.
 12. The polymer filmcomposition of claim 10, wherein the principal solvent is a diol or aderivative of a diol.
 13. The polymer film composition of claim 12,wherein the principal solvent is a cyclohexanedimethanol.
 14. Thepolymer film composition of claim 1, wherein the principal solvent has aClogP between from about −2 to about 2.6.
 15. A film-forming compositionfor forming a cold water soluble film, the composition comprising: fromabout 60% to about 95% of polyvinyl alcohol of an average molecularweight from about 3,000 to about 30,000; from about 5% to about 40% ofpolyvinyl alcohol of an average molecular weight from about 30,000 toabout 200,000; optionally, from about 0% to about 30% of a principalsolvent; and wherein said polyvinyl alcohol has a degree of hydrolysisof less than about 90 mol %, and wherein a film formed from thefilm-forming composition will dissolve in a beaker of water at atemperature below about 68° F. in less than about 5 minutes withagitation.
 16. The polymer film composition of claim 15, wherein thefilm formed from the composition will dissolve in a beaker of water at atemperature below about 68° F. in less than about 3 minutes.
 17. Thepolymer film composition of claim 15, wherein the film formed from thecomposition will dissolve in a beaker of water at a temperature belowabout 68° F. in less than about 2 minutes.
 18. A water-soluble filmcomprising the composition of claim
 1. 19. The film of claim 18, whereinthe film has a thickness of between about 20 microns and about 80microns.
 20. The film of claim 18, wherein the film is a multi-layeredfilm or laminate.
 21. An article of manufacture comprising: a releasablecomposition to be released into an aqueous medium; and a water-solublefilm according to claim 18 encapsulating said releasable composition.22. An article of claim 21, wherein the releasable composition is afabric softening composition.
 23. An article of claim 22, wherein thereleasable composition and the film forming composition comprise acommon principal solvent.
 24. An article of claim 21, wherein thereleasable composition is a detergent for fabric or dish.
 25. An articleof claim 21, wherein the releasable composition comprises a perfume. 26.An article of manufacture comprising: a releasable composition; and awater-soluble film encapsulating the releasable composition; whereinsaid releasable composition and said film-forming composition eachcomprises at least one common solvent.